The present invention relates, in general, to the field of magnetoresistive (MR) sensors and the utilization of the same as magnetometers and magnetic compasses. More particularly, the present invention relates to effective, simplified and highly accurate techniques for MR sensor temperature compensation and magnetic cross-term reduction in conjunction with conventional magnetoresistive sensor designs.
There are a number of conventional magnetic sensor designs and techniques for utilizing them in compassing, navigational systems and other applications currently available. In this regard, representative references include: Caruso et al., “A New Perspective on Magnetic Field Sensing” published by Honeywell, Inc. May, 1998 (hereinafter “New Perspectives”); a Honeywell Sensor Products Datasheet for the HMC1001/1002 and HMC1021/1022 1- and 2-Axis Magnetic Sensors published April, 2000 (hereinafter “Honeywell Datasheet”); a Honeywell Application Note AN-205 entitled “Magnetic Sensor Cross-Axis Effect” by Pant, Bharat B. (hereinafter “AN-205”); and a Philips Semiconductors publication entitled: “Magnetoresistive Sensors for Magnetic Field Measurement”, published Sep. 6, 2000 (hereinafter “Philips Publication”). The disclosures of these references are herein specifically incorporated by this reference in their entirety.
Specifically, the New Perspectives document provides an overview of magnetoresistive and other magnetic sensing technologies while the Honeywell Datasheet provides a detailed description of the particular MR sensors as may be utilized in a representative embodiment of the present invention disclosed herein. The AN-205 application note describes conventional techniques for the elimination of magnetic cross-terms in magnetoresistive sensors while the Philips Publication provides a detailed description of MR sensor functionality including relevant mathematics.